Ok getting alittle p'd with this truck. It is a 04 reg cab silverado. Having some issues with the heating and ac. Before any one says try a search I did and tried what I found.

I have put a new water pump, thermostat, flushed the radiator. Coolant is topped off. Blower motor works fine. I found an actuator under the dash above the hump it works fine. Coolant is going into an out of the heater core. I changed the vent door manually and nothing changed other than cut off the driverside heat. I also pulled the HVAC fuse and let the system reboot its self.

The issue is that I am getting cold air on the middle and passenger side no heat. I cant seem to find another actuator for the outside air door. Does anyone know how to check this? is there even and actuator? All I can see is the one actuator that cuts off heat to the driver side. Also the passenger side defrost doesn't really put off much air, pretty weak. Please somebody help!! I am moving to upstate newyork in a couple months, I can deal with it now since hawaii doesn't get to cold.

I am going to replace the actuator anyhow since the driver side ac went hot today for a little while.

Please lets here any ideas or let me know what to check next or where the other actuators are. Thanks alot.

 

As a matter of fact my friend there are 4 actuators and 3 doors. It sounds to me like you have a Temp. Valve actuator or a Mode Door actuator that's bad. The actuators are as listed: Temprature Valve Actuator- Top and Bottom for a total of 2. A Mode Valve actuator x 1 and a Air Inlet Valve actuator x 1.

 

I was going to reply yesterday that hopefully TorqueWrench would see this thread and add his .02, but I got distracted by my daughter and forgot lol. Is there a chance that the park procedure might help or does it sound like an actuator is definitely shot?

 

awesome time to take the dash apart again. When it is raining I am getting water dripping onto the passenger side floor. So I am going to assume that the air inlet is stuck open.

 

Yeah the Re-Park Sync may fix it, it's always worth a try. Good thinking BudHayes, I forgot about the Re-Park.

 

Now, the water dripping on the floor sounds more like you have a heater core drain tube stopped up.

 

if it was the heater core, wouldn't it be coolant? this is pure water coming out. Gonna search the re park sync.

 

You need a right mix door actuator. Its the one up on top of the HVAC housing under the dash. GM Service Info says pull the dash. Take the dash cover off, unbolt the HVAC ducts and shove them forward and you'll have enough room to get to it. Takes an hour or less.

Sure you can try and recalibrate the actuator but if there is one thats getting flaky the recalibration usually kills that sucker dead. Thats usually how I diagnose one thats not acting right, grab the Tech 2, do a recal and then go get a new actuator(s).

 

^^^^ what he said

 

I think he was referring to the HVAC box, which houses both the heater core and AC evaporator...the water is condensation from the evaporator and the box has a drain hose that goes through the floor, out of the truck. If it gets clogged, water has no where to go so it collects in the HVAC box until it finds a spot to leak out into the cabin